VacantEntry in std::collections::hash_map

VacantEntry in std::collections::hash_map - Rust

Struct VacantEntry

1.0.0 · Source

pub struct VacantEntry<'a, K: 'a, V: 'a> { /* private fields */ }

Expand description

A view into a vacant entry in a HashMap. It is part of the Entry enum.

Source §

1.10.0 · Source

Gets a reference to the key that would be used when inserting a value through the VacantEntry.

§Examples

use std::collections::HashMap;

let mut map: HashMap<&str, u32> = HashMap::new();
assert_eq!(map.entry("poneyland").key(), &"poneyland");

1.12.0 · Source

Take ownership of the key.

§Examples

use std::collections::HashMap;
use std::collections::hash_map::Entry;

let mut map: HashMap<&str, u32> = HashMap::new();

if let Entry::Vacant(v) = map.entry("poneyland") {
    v.into_key();
}

1.0.0 · Source

Sets the value of the entry with the VacantEntry’s key, and returns a mutable reference to it.

§Examples

use std::collections::HashMap;
use std::collections::hash_map::Entry;

let mut map: HashMap<&str, u32> = HashMap::new();

if let Entry::Vacant(o) = map.entry("poneyland") {
    o.insert(37);
}
assert_eq!(map["poneyland"], 37);

1.83.0 · Source

Sets the value of the entry with the VacantEntry’s key, and returns an OccupiedEntry.

§Examples

use std::collections::HashMap;
use std::collections::hash_map::Entry;

let mut map: HashMap<&str, u32> = HashMap::new();

if let Entry::Vacant(o) = map.entry("poneyland") {
    o.insert_entry(37);
}
assert_eq!(map["poneyland"], 37);